A turbofan gas turbine engine used for powering an aircraft in flight typically includes, in serial flow communication, a low pressure compressor, a high pressure compressor, a combustor, a high pressure turbine, and a low pressure turbine. The combustor generates combustion gases that are channeled in succession to the high pressure turbine where they are expanded to drive the high pressure turbine, and then to the low pressure turbine where they are further expanded to drive the low pressure turbine. The high pressure turbine is drivingly connected to the high pressure compressor via a first rotor shaft, and the low pressure turbine is drivingly connected to both the fan assembly and the low pressure compressor via a second rotor shaft.
The low pressure compressor has a plurality of stages, the first stage of which is generally known as the fan stage. A fan duct extends circumferentially about the low pressure compressor to bound the primary flow path. In order for the fan stage to operate efficiently in compressing the working medium gases, the gases must enter the fan stage smoothly with a minimum of perturbations. To accomplish this smooth airflow, a fan inlet spinner is attached to the fan stage to gradually turn the working medium gases into the fan stage.
Working medium gases are drawn into the engine along the primary and secondary flow paths. The gases are passed through the fan stage and the low pressure compressor where the gases are compressed to raise the temperature and the pressure of the working medium gases. The primary flow path is provided by fan platforms located between adjacent fan blades, near the rotor disk. Generally, each of the fan platforms are affixed to the rotor disk via a pin/clevis mechanism. Thus, during operation, axial retention of the pin is required.
Sealing is also desired between the fan inlet spinner and the fan platform to prevent recirculation of air from entering the primary flow path. As is known in the art, the locations of the primary flow path and the pin within a particular engine can make it difficult to provide as separate features a retention feature on the fan inlet spinner body and a recirculation seal. There is therefore a need for improvements in this area.